That is why we are able to keep our island unknown to the world--not to say 'invisible.'" For a moment St.George looked at him speechlessly; then, in spite of himself, a slow smile overspread his face.
"But," he said, "your Highness, there is not a mathematician in the civilized world who has not considered that problem and cast it aside, with the word that if fourth-dimensional space does exist it can not possibly be inhabited." "Quite so," said the prince, "and yet here we are." And, if you come to think of it--as St.George did--that is the only answer to a world of impossibilities already proved possible.

But the vista which all this opened smote him with irresistible humour.
"Ah well now, I suppose, your Highness," he said, "that our ocean liners sail clean through the island of Yaque, then, and never even have their smoke pushed sidewise ?" The prince laughed pleasantly.
"Have you ever," he asked, "had occasion to explain the principles of hydraulics, or chess, or philosophical idealism to a three-year-old child, or a charwoman?
You must forgive me, but really I can think of no better comparison.

I am quite as powerless now as you have been if you have ever attempted it.

I can only assure you that such things _are_.

Without Jarvo or Akko or some one who understood, you might have sailed the high seas all your life and never have come any nearer to Yaque." St.George reflected.
"Is Yaque the only example of this kind of thing," he asked, "that the Fourth Dimension would reveal ?" "By no means," said the prince in surprise, "the world is literally teeming with like revelations, once the key is in your hands.